Question

Answer the following in one statement:
How are convection currents formed?

Answer 1

1. In convection, the molecules of a liquid or a gas move in currents.
2. When the liquid, or gas, is heated, some of the molecules begin to move faster and farther apart.
3. This results in an increase in the volume and decrease in the density of that part of the liquid, or gas.
4. Because it is less dense than the surrounding liquid or gas, the heated portion rises.
5. To fill this gap, more dense and cool portions of the liquid or gas come to its place.
6. In this way, convection current is created in liquids and gases.

Thus, convection currents are formed as a result of the variations in the density of liquids and gases with temperature.